The idea of providing a tape monitoring system for tape applicator is not in itself new Applicant is aware of U.S. Pat. No. 4,855,006 Issued Aug. 8 1989 to Marchetti; U.S. Pat. No. 5,507,907 issued Apr. 16, 1996 to Kropp et al; U.S. Pat. No. 5,735,101 issued Apr. 7, 1998 to Lam; and U.S. Pat. No. 7,665,498 issued Feb. 23 2010 Bredl et al. Marchetti teaches a system that uses a cam sensing means that detects rotation of a cam the rotation of which is generated by tape movement and provides a warning signal if the tape is not moving as required. Lam teaches the use of a feeler arm to detect the tape. Kropp et al provides an improvement over Marchetti and teaches the incorporation of a tape dispensing sensor and a box presence sensor connected to a control system that in effect shuts down the machine if an error signal is detected. This patent also describes a tape supply sensor which senses the tape on the tape roll and sends an error signal if the tape roll is about to be depleted. Bredl et al teaches a more elaborate system than the teachings of either of the above patents but uses much of the teachings of Kropp et al., provides for the tape dispensing sensor and the object detecting system (box detector) being positioned independent of the tape head and uses a relatively complicated system that includes comparing velocity, counting, encoding, measuring current of the conveyor motor, etc., to generate signals for the control system.
Adhesive tape closure is one of the most common methods used in the packaging industry to seal the top and/or bottom of a carton due to its simplicity and low cost of materials and equipment, particularly in the foods and drugs industry since it can provide a dust-proof carton closure. However, it is also recognized in the packaging industry that there are two major considerations regarding tape sealing: (1) Restricted tape Length: A roll of tape can seal an average of about 2,000 carton (top only) so that the tape supply roll has to be replaced depending on the production rate about once an hour; and (2) tape quality and application variants: the quality, material, thickness, adhesive formula and the release coating of adhesive tape is not always consistent which in itself may impose problems during the taping operation and the carton taping operation is intermittent (e.g. between cartons there is no tape being applied) so that the tape being applied is subjected to varying speeds, stresses and tensions during each carton taping cycle, and which result may cause tape snap back after cutting, flagging, tape breakage, and other problems such as no tape, tape not cut and other undesirable conditions. Other issues related to taping include temperature; substrate surface condition; adhesive penetration; adhesion holding force; under-filled carton; shelf life of tape; handling of tape roll; tape applicator; dull cutting blade and carton jamming caused by the tape applicator, etc. are factors of production down-time and defective carton closure in tape sealing.
One of the biggest issues with current machines without suitable warning devices, etc. is where the operator cannot easily determine the amount of tape remaining which in some cases results the machine operating after tape roll is completely depleted and untapped cartons discharge. In many cases this problem is exacerbated as cartons with the top or bottom flaps un-taped go unnoticed. Most tape being used is clear and transparent which adds to the difficulty of visual inspection for un-taped cartons. This problem is even more significant with automatic or semi-automatic equipment.
There are many tape detection sensing systems that have been proposed and that suggest different methods to address the abovementioned problems, however, the majority of tape applicator or taping machines currently used are not equipped with any tape monitoring systems.
There are a number of reasons end-users do not use the tape monitoring systems currently available:                (1) High cost: The monitoring system has to monitor two separate tape applicators in an off-set top and bottom positions in one machine which requires many sensors, connections and wiring as well as separated programs or control circuits for each tape applicator. It is only possible to install the system to the machine at the factory with many modifications, wiring and programming involving highly qualified personnel. The system involves engineering and customization for different makes and models of taping machine and thus is not suitable for mass production and becomes a very significant cost when applied to a taping machine. (see U.S. Pat. No. 7,665,498; and U.S. Pat. No. 5,507,907 referred to above).        (2) Complexity: All tape monitoring system in the market uses a control panel mounted on the machine with a programmable Logic Control (PLC) or electrical control circuit and human interface to turn on; off, and reset the system, the control is mounted on the taping machine with sensors connected to the tape applicators (see U.S. Pat. No. 5,735,101)) and photo sensors on the conveyor or the machine frame (see U.S. Pat. No. 7,665,498) for carton detection. The wiring and connections have to allow machine adjustments and disconnection of the tape applicator from the taping machine. Only qualified electrician can service, adjust or repair the system, which discourages users with limited in-house technical personnel.        (3) Ease of use/Effectiveness: Most of the tape monitoring systems involve sensors and power connections between the tape head or the tape roll holding arm to the control panel which is inconvenient and subject to damages since the tape head requires frequent removal from the machine for replenishing of a depleted tape roll, the wires have to be disconnected for removal and reconnected for re-installing. In some cases, the operator may just ignore the time consuming connection, particularly the electrical connection to the bottom tape applicator and as a result the system is inoperative (U.S. Pat. No. 5,735,101 and U.S. Pat. No. 5,507,907); A pneumatically operated system requires an air supply connection to the tape applicator (U.S. Pat. No. 4,855,006 (Marchetti)). An extended length cable or pneumatic hose may be used for connection to the tape applicator without disconnection; however, it is undesirable to incorporate an unprotected loose length of cable or air hose as this is hazardous and can easily result in system damage.                    Furthermore, all systems provide an ON/OFF switch to power the system and a Reset switch to disable and reset the alarm signal. Operators tend to forget to reset the system after attending to the problem or sometimes may just turn off the system if the distress signal is too annoying. The present invention teaches a system that includes automatic shut off and reset of the monitoring system to thereby significantly reduce this operator problem.            Some tape monitoring systems incorporate the signal output from the monitor to turn off the machine, which is not preferable for most automatic production operation since it may cause more carton or product jamming problems to the up-stream packaging process causing more production down time (U.S. Pat. No. 5,507,907 and U.S. Pat. No. 4,855,006).            The normal practice is to maintain a non-stop production process, re-taping the defective carton manually or with an off-line semi-automatic tapping machine.            Tape monitoring systems available in the market do not have an effective system of detecting and warning of “Case-jamming”. A solution that addresses the “carton-jamming” problem during the taping operation is not known in tape monitoring systems. The tape applicator is a mechanical device with tape applying rollers that intersect with the incoming carton and are moved by the carton during the taping operation which applies forces between the carton and machine that must be overcome. Carton stalling or jamming occurs is more prevalent when tapping light weight, under-filled or soft cartons which may collapse when tape is being applied. This undesirable condition occurs even with normal well-packed cartons where the commonly used conveyor belt is badly worn or has not been properly adjusted to provide sufficient force to move the carton through the tape applicator. The present invention is able to detect and provide a warning for this condition.                        (4) Food Safety Modernization Act (FSMA) by USFDA: A new law that has come into force in 2011 as a response to a succession of food recalls in the US has stringent regulations imposed on food and drug related products. According to Packaging Machinery Manufacturers Institute (PMMI), the new law has a major impact on packaging equipment manufacturers in setting higher standards and requirements to provide equipment with a “clean design” or accessibility for cleaning, eliminating any potential area of contamination. Most mechanical parts can be converted into stainless steel with ease of removal for wash-down and vacuum cleaning. Among all “clean design” criteria, electrical instruments, multiple wiring and connections are the most difficult design issues since all these devises cannot easily be removed for cleaning. Cleaning on electrical devises can also be hazardous if not performed properly. Most electrical cables and instruments generate heat which propagates bacteria growth. The food and drug industry is the major user of tape and taping equipment. As opposed to most tape monitoring system in the market, the present invention to address the “clean design” criteria as required by FSMA.        
The present invention provides solutions to some of the above problems by providing a system that is less costly to install and that eliminates the necessity for loose lengths of cable or air hose and reduces wiring and connections within the system and between the tape applicator and the machine.